Edge preparation machine and method



June 22, 1965 R. HORN ETAL 3,190,097

EDGE PREPARATION MACHINE AND METHOD Original Filed June 20, 1960 7 Sheets-Sheet 1 E Q b I N llO ll 204 lll O a Q 26 3 J es s 2 O Q o I l9 l oz o4 3 2o 80 FIG. I

INVHVTORS RUDOLPH HORN KENNISON L. VOWELL ATTORNEY June 22, 1965 R. HORN ETAL 3,190,097

EDGE PREPARATION MACHINE AND METHOD Original Filed June 20. 1960 7 Sheets-Sheet 2' RUDOLPH HORN KENNISON L. VOWELL l ATTORNEY June 22, 1965 R. HORN ETAL 3,190,097

EDGE PREPARATION MACHINE AND METHOD Original Filed June 20. 1960 7 Sheets-Sheet 3 RUDOLPH HORN KENNISON L. VOWELL ATTORNEY June 22, 1965 R. HORN ETAL 3,190,092

EDGE PREPARATION MACHINE AND METHOD Original Filed June 20, 1960 7 Sheets-Sheet 4 U FIG. 4

RUDOLPH KENNISON L. VOWEL-L F15. I5 I BY ATTORNEY June 22, 1965 R. HORN ETAL EDGE PREPARATION MACHINE AND METHOD 7 Sheets-Sheet 5 Original lfiled June 20, 1960 INVENTORS KENNISON L. VOWELL y RUDOLPH HORN 8 WM FIG.

ATTORNEY June 22, 1965 R. HORN ETAL EDGE PREPARATION MACHINE AND METHOD Original Filed June 20, 1960 7 Sheets-Sheet 6 I as ll H llj -226 FIG. 9

FIG. 7

uwuvrons RUDOLPH H N OR KENNISON L. VOWELL B ATTORNEY June 22, 1965 EDGE Original Filed June 20, 1960 R. HORN ETAL 3,190,097

PREPARATION MACHINE AND METHOD 7 sneets-snet 7 146 r4 I34 i// I44 u g I a.

INVENTORS RUDOLPH HORN KENNISON L. VOWELL ATTORNEY United States Patent Office 3,190,097 Patented June 22, 1965 3,190,097 EDGE PREE'ARATION MACHINE AND METHOD Rudolph Horn and Kennison L. Vowell, Los Angeles, Calif., assignors to North American Aviation, Inc. Original application June 20, 1960, Ser. No. 37,146, new Patent No. 3,120,915, dated Feb. 11, 1964. Divided and this application Sept. 18, 1963, Ser. No. 318,457 4 Claims. (Cl. 72-210) This application is a division of our application, Serial No. 37,146, filed June 20, 1960, issued as US. Patent No. 3,120,915, on February 11, 1964.

This invention concerns method and apparatus for trimming an object to produce anedge or a surface of extremely precise form and accurate dimension. More particularly, the invention contemplates an improved method and means for trimming an edge on thin members in sheet form to provide a perfectly straight edge free of bends, burrs, or rounded corners.

The invention disclosed herein is applicable to the trimming of any article which can be held between clamps while a portion thereof is severed from the article to provide, a sharp, cleanly cut and dimensionally accurate edge regardless of the precise composition or dimensions of such article. However, a particular need for this invention arose in connection with the trimming of relatively thin sheets of advanced alloy material during fabrication of ultra high speed type aerial vehicles, wherein the techniques and materials formerly employed for conventional supersonic aircraft and missiles are often unsatisfactory. Structure used in vehicles of the stated type must be capable of withstanding the extreme temperatures and stresses encountered during operation of the vehicle. As a specific example, thin sheet metal skin surfaces such as formerly used in aircraft construction are totally inadequate, and reinforced skin surfaces of honeycomb sandwich panel type are necessary. In the manufacture of such panels, thick slabs of honeycomb core material of thin metal foil are accurately cut to produce uniform thickness throughout the section, and are thereafter oven brazed to sheet metal top and bottom panel surfaces. Materials of construction formerly in wide use are largely unsuitable in vehicles of the stated type, and have of necessity been discarded in favor of advanced type alloys of increased hardness and strength, with consequent decrease in machinability, requiring specialized fabrication techniques.

Fabrication of honeycomb sandwich panels in sections.

of the type referred to above involves the use of relatively huge expanses of thin sheet metal as little as .006 inch thick for the top and bottom panel surfaces. Due to inherent limitations in the rolling process used for manufacture of advanced type alloy sheets, the maximum width obtainable in a sheet .006 inch thick is sixteen feet. Therefore, it is necessary to use a plurality of the stated sheets, joined together along their adjacent edges, to form top and bottom surfaces in the panels described above. Welding is the most acceptable method of joinder between such sheets, based upon consideration of factors such as cost, overall strength, and economy of weight for welding as against various alternative fastening means.

. However, welding of material in extremely thin sheet form along edges of the length involved in the problem situation stated above requires specialized techniques not heretofore known in the welding art. In all known methods of fusion welding, the welding temperature is often much higher than the melting point of the base metal, and some of this heat permeates the base metal surrounding the weld area. Thermal changes such as expansion and contraction are virtually unavoidable, as

well as changes in physical characteristics such as strength and ductility. Moreover, metallurgical effects such as crystallization and heat treatment occur due to the application of welding heat.

These eifects are particularly severe in the case of joining two light metallic members to each other, partly due to the high rate of thermal conductivity in thin metallic sections and partly due to the relatively low masses of metal involved. Where the mass of metal in two parts joined by welding is insufficient to absorb safely the welding heat within the time required to eflfect fusion of the materials, such as in the case of extremely thin metal sections, the welding problem is especially acute due to the exaggerated effect of residual and heat stresses resulting from the welding operation. Residual stress results from the rapid and uneven cooling of molten metal in the area of the Weld, and from phase transformation of the granular structure in the base metal beyond the area of the weld. Residual and heat stresses have a highly deleterious effect upon the strength of the welded article, and produce severe distortion in the case of thin walled members.

In welding thin metallic sections by use of methods heretofore known, the stress and distortion effects described above are unavoidable and acute. Strong, clean and accurate welded joints have been heretofore unobtainable in welding thin walled metallic sections such as encountered in the problem situation described herein. Therefore, known techniques of fabrication are unacceptable, since accurate fitting of welded components in vehicles of the stated class is essential, especially where large sections must be joined together along continuous high-strength weld seams, and avoidance of the slightest distortion and resulting misalignment are commensurately important. Such distortion is further unacceptable in view of the extremely close tolerances required for joinder of the welded sheets to honeycomb core material,

wherein a maximum clearance for brazing between the core and the sheet is on the order of .0010 inch throughout the entire area of the stated panel.

The most expedient method for effecting a satisfactory weld of the type involved in the problem situation discussed above requires the formation of an upturned flange or lip along one or both of the edges to be joined, and the accurate alignment of both edges closely adjacent each other throughout their entire length. The metal sheets are positioned in a special welding machine in the stated relationship. Thereafter, precision welding is accomplished by a high temperature Welding head which moves rapidly along an automatically controlled path of travel and burns through the upturned flange or flanges to produce a Weld puddle which fuses the two adjoining edges, together in a single pass. Thus, a minimum of weld heat is absorbed by the base metal, and the amount of distortion resulting therefrom is commensurately diminished.

In accomplishing the highly specialized welding process referred to above, careful preparation of the edges to be thus joined is critically important. For example, any waves orrdents along either edge would vary the clearance between the welding head and the precise area to which Welding heat is applied. Variations in the stated clearance would produce non-uniform intensity and distribution of heat, each of which affects the strength of the completed weld joint, the cooling rate throughout the area of the weld, and the size of the weld area, all of which in turn produce distortion which cannot be remedied by mere rolling, heat treating or any known means without considerable weakening of the weld seam. Similarly, gaps between the adjacentedges of the sheets before welding would have cumulative effects on the condition of the to be welded. Each of the edgesmust be absolutely straight, perfectly flat, squarely cut and free, of waves,

' bends, burrs and-dents; Since the rough trimming operation performed d ring manufacture of sheet metal such 'as that described hereinabove does not produce the nec essary dimensional accuracy for precision welding in the manner stated, the sheets require special: cutting prior 7 to the Welding operation. 7 V V In the prior art, edge trimming or contour cutting of sheet metal is normally accomplished by so-called'slitting devices .compr' ing two rotating wheels with their blade edges overlapping in the mannerof a household opener. In devices or" this type, the cutting wheels both rotate but are otherwise stationary and the material to be cut is moved translationally, through the 'rotating' cutters. Use of such devices entails the application or" force on the material to steer the same through the cutting 4i improved accuracy by severing a portion therefrom along a precise predetermined cutting path.

It is a further. object of this invention to provide appara tus as set forth in these objects incorporating means by which extremely accurate trimming may be accom-' plished without necessitating movementof the material being trimmed. a e

Also, it is an additional object of the invention disclosed herein to provide apparatus for trimming with wheels, to produce 'a relative path of travel which'will 3 result in the desired shape of cut.

or angular deformations which produce permanent dents or dings at their apices,' material"of this type cannot besteered through any device requiring tugging or pushing of the material, hence conventional siitters are unsuitable for trimming such sheets. Moreover, slitters of the type mentioned above cannot make perfectly straight cuts through material which is tapered in thickness, due to variation in the lateral force exerted on the material bythe cutting action of the wheel blades.

rial that the device which accomplishes the trimming must permit accurate cutting along a predetermined path without necessitating movement of the material bytheapplication of force thereon.

Also, since his a vital consideration in'the problem statement set forth above that'the trimmed edge be perfectly straight regardless of the hardness of the material being trimmed, or variations'in its thickness, fit is'a further requirement'that thedevice which accomplishes the trimming incorporate means preventing displacement of the material by variations in. the force exerted on the material by' the cutter during its movement along a predetermined straight'path.

Since sheet'metalrof .086 inch thickness and i6 feet width cannot even be lifted in the unrolled condition without causing canning improved accuracy material of tappered or uniform thickness.

'It is'a further object of the instant invention to provide apparatus for trimming material withimproved accuracy by severing a portion therefrom so that theresulting edgeissquarely cut and free of burrs, bends, waves and rounded portions.

. It is an additional object of this invention to provide apparatus for, trimming material with improved accuracy including means permitting precise adjustment ofithe apparatus to accommodate materials of different thicktress or hardness, "or different conditions of the trimmed cogeg' g V i It is also an object of the invention herein disclosed to provide apparatus for trimming material with improved accuracy by severing a. portion therefrom along a precise predeterminecl cutting path so that the severed portion may vary in width from .905 inch to several feet. I

7 Other 0 jccts and advantages will become apparent upon a closereading of the following detailed description or" an illustrative. embodiment of the inventive concept,

reference being had 1 to theJaccompanying drawings,

wherein:

FIGURE -1 shows, in. side elevation and partly in sec tion, a general'view'of the I apparatus disclosed herein, FIGURE 2 shows a frontelevation of the apparatus of FIGURE 1,

FIGURE 3 shows a side elevation partly in section of a portion of the apparatus of FIGURE! in slightly larger detail, i

FIGURE 4. shows an enlarged side elevation of i 7 a portion of the apparatus of FIGURE 1,

FIGURE 5'shows a cross-sectional view. taken along line 5-5 r FIGURE 3,

Moreover, due to' the' ueedfor extreme accuracy in providinga perfectly square edge-as necessary for wel-ding in the manner describe above, it is a furtheifrequirement in any device used for the purpose here involved. that the resulting edge is free of burrs, bends, waves and rounded that means he provided to remove metal so.

portions' p In addition, since the problem statement described above includes use of material of tapered or others-vise non-uniform thickness for use in the fabrication of structures in which "load stresses are not uniform, it' is a further requirement in the device for trimming" such material that means be incorporated for adjusting the device to produce precision cutting of edges regardless; 65

Also, since the amount requiredto be severed from a sheet of material in order to producea perfectly straight of such-variations in thickness.

edge may'vary consider-ably along the entire width of such sheets, the device fortrimming such sheets is required to sever accurately 'any'amount from the edge which; may vary from a thinsliver to a relatively wide strip. r Accordingly, it is aprincipal object of the instant invenltion to provide apparatus for trimming material with FIGURE o'shows a front elevationof one end oi the reaction stress 'box'beam shown in cross-section at the top or" FIGURE 1,

FIGURE 7 shows an end viewin elevation of the box beam mount'ofFIGURE'Q i i V FIGURE 8 shows in side elevation and partial sectron a portion of internal structure ofrthe apparatus of FIGURE 31in larger detail,

7 FIGURE 9 shows a perspective view of the structure of FIGURES,

FIGURE 10 shows an etd view in elevation-of the structure of FIGURES 8 and 9,

FIGURE 11. shows a plan view,

the vertical brake and adjusting means for the apparatus of'FIGURE 1,

FIGURE 12 shows a cross-sectional view taken along line 12 12 ofFIGURE'lI, I

: FIGURE '13 shows aperspective view, partly secs:

tion, of the structure shown by FIGURES 11 and 12,

FIGURE 14 shows an enlarged side elevation,ipartly in sect on, of a portion of the apparatus of FIGURE :1, with the V V and With reference to the drawings described above, and

particularly t'oFIGURE- 1, the apparatus disclosed herein I includesarcuate severance means which may take the form of arotary cutter 1 0 mounted inclose proximity to one edge of a table support 12;. by means of which an element" 7 such as a sheet of metal as indicated by reference numeral otherwise nonpartly in section, of I rotary cutter replaced by a flange folding wheel,

FIGUREYIS'shows a general view of the supporting;

a housing support member 22 as shown in FIGURE 5.

Member 22 has a channel 21 cut in the top surface thereof with undercut channel walls 24 on each side of channel 21, by means of which member 22 is suspended from a slidable element in the form of roller support 32 having beveled sliding surfaces 38, 40 on either side at the lower edges thereof. As shown in FIGURE 5, undercut channel walls 24 of member 22 contact beveled surfaces 38 and 40 and are in sliding engagement therewith. Roller support 32 is in turn suspended from a member 42 which has underhanging tracks 48 and 50. The upper surfaces of these tracks are in sliding contact with the lower surfaces of two overhanging tracks 44 and 46 located on either side of roller support 32. Upward force is exerted on housing support 22 by four springs attached to member 42 and denoted by reference numeral 56 in FIGURE 5 which counteract the downward force of housing support 22. Springs 56 thus considerably reduce or eliminate the friction which would otherwise be exerted between undercut channel walls 24 and beveled sliding surfaces 38 and 40.

With reference to FIGURE 9, roller'support 32 may be seen to function as the main support for two followers or rollers 26 and 28 rotatably mounted by pivots 29 and 38, respectively. Rollers 26 and 28 are constantly maintained in rolling contact with surface 25 of cam tracks 23 as shown in FIGURE 3. Roller support 32 also contains a guide slot 34 in which guide pin 36 is slidably movable as shown by FIGURE 8. Roller support 32 also includes a flange 33 on which a spring guide 35 is integrally formed. Spring guide 35 is contained within a heavy duty spring 70 shown in FIGURE 3, one end of which bears on flange 33 and the other against a bearing plate 72. The force exerted by spring '70 on flange 33 may be varied by turning adjusting screw 74 which is rotatably journalled in threaded engagement with boss '76 and equipped with hexagonal head 78 to permit rotation of the adjusting screw.

Thus it may be seen that roller support 32 is slidably supported within suspension member 42 to permit movement toward the left or right as shown in FIGURE 3, and is urged toward the left by the force of spring 70. The relative position of roller support 32 with respect to mem: ber 42 is determined by the contour of surface 25 on cam track 23, upon which rollers 26 and 28 move in continuous contact. Housing support 22 is slidably mounted on roller support 32. The relative position of housing support 22 with respect to roller support 32 is determined by the position of handle 58 shown in FIGURES 1 and 3. Handle 58 is mounted at one end of shaft 60, the other end of which is provided with threads 62. Threaded end 62 of shaft 60 is threadedly engaged in a hole (not shown) in the right-hand end of housing support 22 as drawn in FIGURE 3. A gage 68 is mounted on flange 33 of roller support 32 by means of hole .66 shown in FIGURE 9, this gage being provided withan indicator rod 64, the end of which bears against the right-hand end of housing support 22 as shown in FIGURE 3. When handwheel 58 is rotated, housing support 22 is moved to the left or right with respect to roller support 32, this'change in relative position causing corresponding movement of indicator rod 64, the extent and direction of which is indicated by gage 68.

Lateral adjustment of rotary cutter 10 with respect to bar knife 18 is thus accomplished by means of handwheel 58, the rotation of which causes leftward or rightward movement of housing support 22 and hence of cutter 10. After the position of rotary cutter 10 has been adjusted by the stated means, this position may be continuously maintained by means of a brake provided for this purpose. This brake comprises a wedge 84 shown in FIGURE 5, this wedge being'contacted by a threaded shaft 82 threadedly engaged in a hole within housing support 22. Shaft 82 may be rotated by means of handle provided for this purpose. Rotation of shaft 82 causes force to be applied toward the right in FIGURE 5 so that wedge 84 bears with increasing force on beveled sliding surface 40, and the reaction from this force pulls undercut channel wall 24 more closely against opposite beveled sliding surface 38, securely clamping housing support 22 tightly against roller support 32, and preventing relative move ment Lherebetween while the brake is engaged.

As shown by FIGURE 3, suspension member 42 is aflixed toa vertically adjustable support 90. Support includes a slide plate 91 at one side thereof, this plate contacting and slidably engaging a slide block 92. Block 92 is fixedly mounted on carriage frame 100, which moves neither laterally nor vertically as seen from FIGURE 3, but is capable of translational movement toward the right or left with respect to table 12 as seen in FIGURE 2.

Vertical adjustment of rotary cutter 10 with respect to table 12 is manually accomplished by handwheel 124 shown in FIGURES 2 and 3. Handwheel 124 is mounted on a shaft 125 which is rotatably journalled within a housing 126. Shaft 125 is provided with a bevel gear 128 which is rotated by turning handwheel 124. Gear 128 is operatively engaged with bevel gear 132 mounted atop a threaded shaft 134. Shaft 134 is pivoted between bearing mounts 136 and 138, and is prevented from vertical movement relative to adjustable support 90 by means of retainer ring 142 and flange 143 contacting the upper and lower surfaces of bearing 138, respectively. Shaft 134 is threadedly engaged within a relatively immovable nut 144, sothat rotation of shaft 134by means of handwheel 124 causes vertical movement of shaft 134, adjustable support 90 and slide plate 91. Since nut 144 is fixedly attached to slide block 92 which forms part of vertically immovable frame 100, slot 146 in plate 91 is provided as shown in FIGURES 11-13, in order to permit relative movement between the stated nut and plate.

A brake generally corresponding to that for holding rotary cutter 10 in a relatively fixed lateral position with respect to table 12 is also provided to secure cutter 10 against changes in vertical position after vertical adjustment has been completed. As shown by FIGURE 3, handle 108 is provided at one end of the rotatable shaft 112 which is supported within a steady mount 114.

Threaded end 116 of shaft 112 isoperatively engaged by corresponding threads within an opening in wedge or brake 118 as may be seen from FIGURES Hand 13. A beveled braking surface 122 forms one wall of a slot 123 which is provided in slide block 92, so that wedge 118 moves vertically in the stated slot when rotation of threaded shaft-134 causes vertical movement of slide plate 91 and related structure.

Thus, it may be seen that rotation of shaft 112 by means of handle 108 causes movement of wedge 118 either toward or away from beveledsurface 122. After the vertical position of rotary cutter 10 with respect to table 12 has been adjusted byhandwheel 124 in the manner set forth above, vertical brake handle 108 may be operated to cause movement of wedge or brake 118 into close contact with surface 122, securely holding slide plate 91 against slide block 92 and preventing relative movement therebetween.

As shown by FIGURE 1, r-otary cutter 10 and all its adjustment and supporting means described above are mounted on carriage frame 100. Carriage frame 100 is movably guided and supported by means in the form of upper and lower guide rails and 150, respectively,

I and gear rack 140, so that V movable with respect to stationary main frame 129; t This relative movement may be caused by manual means a the statedframc is linearly or by suitable mechanical devices, and in'the preferred embodiment is 'motivated by a constant speed electric motor 160 shown in FIGURE 2, actingon'rnain driving sprocket 156 through variable speed transmission 152iand gear box 154, all of which are mounted on vertically immovable'supper carriage frame 110 as shown in FIG- URE 1. Main driving sprocket 15-5 in turn drives sprocket 162 by means of chain 158, as best seen FIGURE 1; Q

Sprocket 162 rotates segmented shaft 164,on the left end of which a pinion 148 is. affixed. Pinion 148 is mounted with its gearteeth interengaged with those on gear rack 149 so that rotation of the stated pinion causes translational movement of shaft 164, and hence of frame 1% in which the stated shaft is rotatably journalled.

The right end of segmented shaft led-is provided with a sprocket 94- 'r-otatably mounted within housing 96 as shown in FIGURE 1. 'Sprocket 94'drives sprocket'162' by means of chain 98. Sprocket lflz isrotatably mounted within a housing 1414 which is affixed at the'lower end of vertically adjustable support 90 .1 Housing is also affixed to support 9% at its upper end as shown in FIG URE 1, so that vertical movement of the stated vertically adjustable support 5 9 by means of handwheel 124 in' the'manner set forth above will produce corresponding vertical movement of housings 6 and 104 and sprockets )4 and 102 respectively mounted therein.

ed within structure afiixed to carriage frame 160 which is Since the right-hand'end of segmented shaft 1::4 is pivotally mounttable 12 by suitable brackets or braces such as hollow col- 'umns 299 shown in FIGURE 15. Means are provided forapplyi'ng downward clamping force on clamp member 14-, the stated means comprising a plurality of pneumatic or hydraulic cylinders 1%2, each of which applies force to a push rod 1% through a piston rod 194 in contact therewith; Push rods 196 apply downward force'to upper clamp member ll i' when cylinders 192' are prossurized. An annular flange at 'theupper end of each a push rod196 contacts a compression spring 198 as shown 1,. so that upward force from the stated in FEGURE springscause upward moverncnt'ofpush rods 1% when pressure is rcleased'from cylinders 192.

Upward movementrof push rods 196' permits upper clamp member 14- to be raised. Means for raising member 1 are provided in the form of one or more brackets 2G2 attached to stationary main frame 126, to each of which a pneumatic-or hydraulic jack 264 is pivotally not vertically m-ovable,'an intermediate portion of segthreadedly engaged in a lower boss 176 withthe upper end of the stated screw contacting an upper boss 182 in-' tegrally formed on plate 183. Plate 183 is attached to vertically adiustable support- 90by meansof four'bolts 184 which pass through slots 186 and plate 183, With 'bolts 184 in the loosened condition, tension'in chain 98,

may be increased by rotation of tension adjusting screw 178 causing upward movement of the stated screw byreason of its threaded engagement with relatively 'sta- L tionary lower boss 186. Upward movement'ofscrew 178 causes corresponding movement of upperboss 182 and plate 183'. 186, and when the desired tension in chain 98 is achieved,

7 bolts 184 maybe tightened down to hold plate 183usecurely against vertically adjustable frame 90 and prevent relative movement therebetween.

Since operation of motor 160 causes rotationof seg- V mented shaft'164, together with pinion 148 and sprocket 94 mountcdin the left and right end of the stated shaft,

' respectively, as seen in FIGURE 1, translational move 'ment of frame 1% and rotation of rotary cutter ld both occur simultaneously. Means for varying the speed of this translational and rotational movement are provided in the form of handwheel 187 which acts through flexible cable 188 to vary the speed output of variable speed transmission 152. The speed setting of handwheel 187.

is indicated by a gage 189'operatively connected thereto as shown in FIGURE 2, a

' As seen from FIGURES 6 an'djt7, box beam 1952' is mounted atop the main frame 120 by meansof upright This movement is permitted by slots' FEGURE 1. By appropriate electrical connections (not V the edge of sheet 2 overhangingbar knife 8 in theamount secured as shown iriFlGURE 1. A, piston rod 286 opera tively connected within each cylinder 294 is pivotally joined to a rocking lever 2% which is pivotally mounted on main frame 128 by means of pivot pin 210. On'the endof each rocking lever 268 opposite from the point of attachment of piston rod 296 a pull rod 212 is also 'pivotally attached. The lower end of each pull rod 212,

is pivotally attached to an intermediate link 214 in the manner shown'by' FiGURE '1, the stated link being further pivotaliy attached to bracket 216 on upper clamping member-l4. When cylinder 294 is pressurized causing downward movement-of piston rod 2% and corresponding upward movement of pull rod 212, intermediate link 21% applies upward force on bracket 216 and upper clamping member 14, raising the clamping member and tnus freeing the workpiece upon which downward clamping force was formerly applied. A guiding 'link, 218 is' also pivotally connected tobracket 216 in the manner shown by FIGURE 1 to insure that upper clamping member 14- will'be raiseda uniform vertical distance through% out its width and length. Upward movement of pull rod 212 also causes actuation'of a :microswitch ZZ-tdue to operative engagement of actuatingtarm 222. of the micro: switch with the'top end of pull rod 212 as best seen from shown) in the controlcircuit for cylinders 192, actuation of microswitch 224 due to upward movement of pull rod 212 and clamping member 14 may be caused to prevent actuation of cylinders 192 so that downward force may not be applied on the stated clamp member'in opposition to the lifting force applied by pull rods Z12.

Operation I 7 Although the apparatus disclosed herein maybe used to achieve dimensional accuracy. in a variety of diverse materials and shapes, its operation will not differ mate.

rially from the description set forth below in connection with trimming the edge of thin metal sheets such as sheet 2 shown, for example, in FIGURE 3.

of the edge preparationmachine may be commenced by actuating cylinders 192 and'ZG-{i to raise push rods clamp member, 14, permitting sheet 2 to be laid on the top surface of table 12 under clamp member 14'with desiredto be trimmed off. 7 I

Prior'to the actual' trinnning operation, rotary cutter 10 is positioned'with respect to bar knife 18' to produce the desiredchar'acteristics in the trimmed edge,

' a thickness of material being trimmed, but ;'in no case is flange ZZGpassing between yoke membersj226 and opera 7 tively joined thereto by means of pivot pin 22.8. Each, end of box beam 1% is. mounted on frame 129 in the stated manner while frame 12i3'is fixedly; mounted on contact permitted between the edges of rotary'cutter 10 andbar knife 18. Since thestated edgesmerely impose V loads on the-workpiece to cause a rupture due totshear failuretherein, and do not slice completely through the material of theworkpiece, the surfaces of the stated cutter and knife do not scrape past each other in the manner Operation 176 t and pull rods 212,'respectively. This action raises upper l s SEIECF. L on of the stated position will depend upon the type and of scissor blades, for example. Moreover, since the surfaces of rotary cutter forming edge 11 are metallurgically treated to produce maximum hardness, and bar knife 18 is similarly surface hardened, actual contact between the two stated surfaces would tend to produce eX- oessive wear and unevenness, hence is carefully avoided.

From FIGURE 4, it may be seen that rotary cutter 10 is provided with an annular edge 11 formed by the intersection of plane surface 4 and cylindrical surface 6. Plane surfaces 7 and 8 of knife 18 intersect to form a straight edge which cooperates with edge 11 to sever material lying between the two stated edges. Both of the stated edges are precision made to form perfect 90 angles. The lateral distance between surface 4 of cutter 10 and surface 8 of knife 18 may be adjusted by means of handy/heel 58 so that each of the two stated surfaces approaches but does not enter the plane occupied by the other. Thus, with the distal end of a sheet 2 overhanging bar knife 18 in the manner shown by FIGURE 4, the load imposed by cutter 10 on sheet .2 is closer to the distal end there of than the reaction load imposed by knife 18. For optimum results, the lateral distance between surfaces 4 and 8 should in no case exceed an amount equivalent to one-third of the thickness of material being trimmed. The lateral clearance between the edge 11 and surface 8 of bar knife 18 is readable on gage 68 as set forth above and is securely maintained after initial adjustment by rotation of handle 80 to engage brake member 84 in forcible contact with beveled surface 49.

Vertical adjustment of rotary cutter 19 with respect to bar knife 18 is accomplished by rotation of handwheel 124 which causes vertical movement of adjustable support 98 and all structure attached thereto including sprocket housings 96 and 104, suspension member 42, roller support 32, housing support 22 and bearing housing 20. Edge 11 of cutter 10 may thus be vertically positioned so that a line parallel to the edge of knife 18 and tangent to cylindrical surface 6 at the lowermost point thereof will lie vertically above the edge of knife 18 by a distance, the amount of which depends primarily upon the thickness and shear strength of the material being trimmed. Since the surfaces 6 and 7 of cutter 10 and blade 18, respectively, apply loads which cause rupture of the material ther'ebetween due to failure in shear, the lowermost linear segment of surface 6 need not be on precisely the same level as surface 7 of bar knife 18. When the desired vertical position has been established, the rotation of handle 1G8 operates vertical brake 118 to maintain the stated relationship between rotary cutter 18 and bar knife 18 throughout the trimming operation.

After cutter 10 is adjusted in the desired relationship to bar knife 18, and sheet 2 is placed on table 12 with the desired amount of overhang, cylinders 192 may be actuated to apply downward force on upper clam-ping member 14 securely clamping the stated sheet material in the desired position. Motor 160 is then operated to produce rotation of pinion 148 at a speed determined by the position of variable speed transmission control handle 187. Simultaneously with the rotation of pinion 148 and commensurate with the speed thereof, rotary cutter 10 is also rotated by operation of motor 160. Rotationof pin-ion 148 while operatively engaged with gear rack 149 causes translational movement of carriage frame 100 toward the left or toward the right as shown in FIGURE 2 depending upon the direction of operation of reversible motor 160. When carriage frame 108 and rotary cutter 10 are moved laterally, the portion of sheet 2 overhanging the cutting edge of the bar knife 18 is severed with equal accuracy regardless of whether the direction of movement is toward the right or the left as viewed in FIGURE 2.

Severance occurs by reason of the load progressively applied by surface 6 upon the upper'surface of the work- .piece during translation and rotation of cutter 10, such load being reacted by surface 7 of bar knife 18. It may be seen from FIGURE 4 that the areas upon which opposing forces are applied by the stated surfaces to sever a portion of the workpiece are in close juxtaposition but never precisely in contact with each other. This results from the minute but definite lateral distance between the vertical planes defined by surfaces 4 and 8 of cutter 19 and knife 18, respectively. Thus, the area in which the shear load is imposed by cutter 10 is laterally displaced from the area in which the reaction force from such load is imposed by bar knife 18. Rupture of the material of the workpiece occurs when the material fails in shear in a plane of severance indicated by the broken line in FIG- URE 4 lying between the closest boundaries of the twomain load support flange 158 and main load support track 7 172. Track 172 is secured to adjacent structure forming part of main frame 120 by means of a segmented 'key 173. The lower portion of the member forming track 172 forms a downwardly projecting lower guide rail 158.

Guide rail 150 is engaged in sliding contact on either side thereof by portions of carriage frame 1% including upwarclly projecting flange 174, so that lateral movement of the lower end of frame 108 as seen from FIGURE 1, for example, is restrained by rail 15%. Restraint against lateral movement at the upper end of frame 108 is exerted by upper guide rail and flange 166 in :a manner similar to that described in connection with lower guide rail 150 and flange 174. Thus, it may be seen that frame 100 and structure attached thereto is entirely supported by track 172 insofar as vertical load is concerned, while movement along the stated track caused by operation of pinion 148 engaging gear rack is guided by upper and lower guide rails 1'30 and 150, respectively.

Continuous accurate lateral stability of rotary cutter 10 with respect to bar knife 18 throughout the distance traversed by carriage frame .100 and structure supported thereon is maintained by means other than those described above for guiding and stabilizing the translational movement of frame 100. Lateral movement of rotary cutter 16 with respect to bar knife 18 is controlled by means which are structurally isolated and independently operable from the remainder of the supporting structure. From the structure described above and disclosed in the drawings, it may be seen that the lateral position of cutter 10 as viewed in FIGURE 1, for example, depends entirely upon the lateral position of cam rollers 26 and 28. This results from the fact that rotary cutter 10 is secured to a drive shaft 19 laterally immovable within bearing housing 28 which is clamped in constant relationship tomember 32 upon which cam rollers 26 and 28 are mounted. Thus, if cam rollers 26 and '28 could move to the right causing corresponding movement of member 3-2 against the force of spring 70 while wedge '84 is holding bearing housing 20 in constant relationship with member 32, the stated housing and rotary cutter 18 would necessarily move toward the right the same amount as rollers 26 and 28. The lateral position of rollers 26 and 28 is controlled throughout the translational movement of the said rollers by the contour of surface 25 of cam track 23 as shown, for example, in FIGURE 3. The outer surfaces of cam rollers 26 and 28 and surface 25 are metallurgically treated to produce maximum hardness. Moreover, the stated rollers are precision made to provide accurate roundness, while surface 25 is accurately formed to produce a smooth, straight reference plane of utmost precision. Spring '78 functions to apply tremendous force upon roller support 32 which transmits this force to hold cam rollers 26 and 28 secure- ".1 Sit 1y against surface 25 at all times. Accordingly, the precise 1 lateral relationship betweenrotary. cutter 1d and bar knife 18, as initially established by lateral adjustment control handle 58, indicated by gage Gib-and securely held by brake means 46, 8d, 82 and 34, is continuously maintained a by the straight and undeviating line of movement traversed by cam rollers 25 and 23 during their contactwith cam s a es? this effect, four springs 56 are mounted in the manner dc scribed above to exert compressive force between suspen track surface 25. Moreover, any jarring-movement or lateral inaccuracy in the path of travel of carriage frame 19!) and structure afixed thereto will not produce any variations in the path traversed by rotary cutteriddur:

' ing the edge trimming operation due to the arrangement of parts described above; 7

Accuracy in the cutting 'actlon between rotary cutter it) 7 and bar knife 18 is further preserved in the apparatus de scribed above by certain uniquefeatures of the means for applying clamping force on-sheet 2. Tremendous downward force maybe applied on clamping member 14,

dependin u on the size, number, and workin ressure of cylinders l92 used in applying 'such force Sincethe quired to prevent the reaction load of this force from causing deflection of main frame 129, guide rails 1-38, ISfiand cam track 23, in such a manner as would'produce damaging effects upon the accuracy and freedom of movement of carriage frame 1% and rotary cutter 1d.

- Means for avoiding deflection of the stated type arepro vided in the form of box beam 1% shown in cross-section in FEGURE I mounted on main frame 12% in the manner shown by FIGURES 6 and l. 'Asnoted above, cylinders 192 in which the downward clamping force of member 14 originates, are mounted on boX beam 15 Therefore, the

' statedforce may exceed 25,000 pounds, means are. re-

reaction from this force'is applied to box beam 19am an upward direction. Since the statcd bea'm is restrained by pins 2.28 at each end thereof, the beam ends cannot move upwardly. Therefore, when cylinders 192 are pressurized,

beam 130 bows upwardly with its greatest deflection atthe center point midway between the two pins 228, altering the position of the beam centerline' in the mannerindicated by angle A shown in FIGURE 6. Since the ends 7 of beam 1% are pivoted on brackets 22% in themanner stated, no vertical force is transmitted through these brackets by the reaction loads applied to the beam. The forces transmitted from brackets 22% to main frame 120 are concentrated in an area and in a direction in which frame 120 offers the greatest resistance and consequently the least deflection. Thus, for example, equal vertical loads applied at either end'of main frame 126 by brackets 220, whether such loads be upwardly or downwardly directed,

would have no effect on the level condition of the racks,

tracks, or rails upon which accuracy and freedom of movement of carriage frame 1% depends. Also, forces in ten sion or compression applied between the ends" of main frame 126 would not cause upward or downward deflection of the stated frame at any intermediate point between such ends. Therefore, it may be seen from the above description and related drawings that accuracy of the cutting action betr een rotary cutter it? and bar knife 18 is unaffected by me reaction forces resulting from theclamp ing action of members 14 and l6. r

Means are further provided to preservethe stated accuracy and facilitate the adjustment of the relative position betwen rotary cutter It} and bar knife'18. As noted inthe descriptive material set forth aboveand shown in FIGURE 5, a sliding'fit occurs between beveled sliding surfaces-38 and 40 on roller support 32 andundercut Chan nel walls 24 on housing support 22; To permit this type the stated looseness between the sliding parts is necessarily eliminated. This action would normally altcr'thelateral. position of rotary cutter-19 because the camrning action of wedge 8 while being moved into operative engagement 7 with surface 4%? moves housing support 22 upwardly at its letter rightend as viewed in FIGURE 3. To eliminate sion member 42 and housing support 22 so that supportx is always held snugly against the bottom surface of roller support 32 regardless of whether wedge 34 i loos 'ened or tightened with respecttosurface .0.: By means of the stated arrangement of parts, no downward sagging at either end of housing supportgi occurs from the looseness of 'the slidiug fit described above when thelaternal brake means 80, 82, 84 is Operated to release the-brake.

Thus the lateral position'of rotary cutter 10 as initially adjusted by handwheel 58 and indicatedbygage 68 is not altered as a result of actuating lateral brake handle 88 to clamp housing support 22 is with roller support 32.

In addition to the above uses and results, the edge. preparation apparatus disclosed herein may be used to, fold accurately a portion of the trim edge of the work-' iece 2 to prepare the same for welding to another similar workpiece. This is accomplished after the above described trimming operation by raising upper clamp element 14 in the manner described above, permitting movement of sheet 2 so that the trimmed edge may be projected over the cutting edge of bar knife 18 to establish an overhang in the amount desired to be folded. :RotarycutterQ above for use with cutter id, causing wheel 230 to rotate and also move translationally along a path parallel and closely adjacent to bar knife 18.

merely bends the'overhanging portions of sheet 2 downward over the cutting edge of knife ,18, forming a perfect 90 bend along-the edge portion or" the workpiece.

Thus, it may be seen that the apparatus disclosed herein may be used for trimming edges of great length on sheets of extreme thinness, to provide a perfectly straight,

precision cut, burrle ss edge; The present inventionhas been found to provide perfect accuracy in shaving as little of fitra certain small amount of looseness between the slidingparts is required. In the stated structure, this looseness permits relative movement between housing support 22 and roller support 32 during adjustment of the lateral position of rotary cutter l ti by means of handwheel 58. However, when lateral brake handle 80 is rotated tosnug wedge 84 tightly against beveled surface 49 afterrotarycutter 10 has been adjusted in the desired position,

as .005 inch'fro'm high temperature advanced alloy steel foil .006 inch thick and'sixteen feet wide, with no burrs, bends, or folds on the finished edge; -Morcover, since.

cylinders 192 may be used selectively and pressuriz'ed in any desired amount to vary the distribution of the clamping force applied by upperclamp member 4, this invention achieves the stated accuracy and results even with,

materials of tapered or otherwise non-uniform thickness, or with material from which a tapered strip must be removed. In'addition, this invention achieves a considerable economic advantage lover. all other known machine,

h i ques for achieving the results and adjectives set forth above. r

While the particular structural details setforth above and in the drawings are fully capable of attaining the objects and providing the advantages herein stated, the structure thus disclosed is merely illustrative and could, be varied or modified to produce the same resultswithout departing from the scope of the inventive concept as delined in the appended claims; V

V We claim:-

1. In apparatus for spinning an edge on sheet material, support means for supporting saidmaterial, stationary straight edge means over which said material may constant relationship" Instead of severing a portion of sheet 2 as accomplished by cutter 10, wheel 230' be placed in overhanging relationship, movable arcuate means for imposing force progressively onsaid 'edge'to deform the same, said force causing said material to fold over said straight edge, adjustable clamping means for holding said material stationary during said folding operation, frame means mounted on said support means, elongate support means forming part of said frame means for movably supporting carriage means, carriagemeans supported by said elongate support means and movable translationally with respect to said frame means, and connection means connecting said movable arcuate means to said carriage means so that translational movement of said carriage means causes similar movement of said movable arcuate means. 7

2. The apparatus set forth in claim '1 above, in which said clamping means includes a stationary lower element and an upper element movable either. to release said workpiece or to clamp and hold said workpiece stationary during spinning thereof, means to move said upper element including cylinder means :for applying clamping force to said upper element, and means to distribute the reaction load from said clamping :forcerso that no vertical load on said elongate support means and no deflection of said elongate support means occurs as a result of said clamping force.

3. The apparatus set forth in claim '1 above, including in addition thereto, means operatively interengaging said carriage means and said frame means to cause translational movement of said carriage means with respect to said frame means, stationary reference means mounted on said frame for controlling the path of translational movement of a follower in contact with said reference means, a follower, said connection means including a spaced relationship with said track, so that substantially 7 all of the vertical load imposed' by said carriage means on said frame means is applied to said track, and said guide rail is operatively engaged with said carriage means so that during translational movement of said carriage means, lateral movement of said carriage means is re-' strained in a direction substantially perpendicular to the path of said translational movement.

References Cited .by the Examiner UNITED STATES PATENTS 7 354,654 12/86 Puddefoot 113-44 711,471 10/02 Chambers et al. 153-29 2,370,666 3/45 Johnson a 153-29 CHARLES W. LANHAM, Primary Examiner. 

1. IN APPARATUS FOR SPINNING AN EDGE ON SHEET MATERIAL, SUPPORT MEANS FOR SUPPORTING SAID MATERIAL, STATIONARY STRAIGHT EDGE MEANS OVER WHICH SAID MATERIAL MAY BE PLACED IN OVERHANGING RELATIONSHIP, MOVABLE ARCUATE MEANS FOR IMPOSING FORCE PROGRESSIVELY ON SAID EDGE TO DEFORM THE SAME, SAID FORCE CAUSING SAID MATERIAL TO FOLD OVER SAID STRAIGHT EDGE, ADJUSTABLE CLAMPING MEANS FOR HOLDING SAID MATERIAL STATIONARY DURING SAID FOLDING OPERATION, FRAME MEANS MOUNTED ON SAID SUPPORT MEANS, ELONGATE SUPPORT MEANS FORMING PART OF SAID FRAME MEANS FOR MOVABLY SUPPORTING CARRIAGE MEANS, CARRIAGE MEANS SUPPORTED BY SAID ELONGATE SUPPORT MEANS AND MOVABLE 